Skip to content
Team chat software · head to head

Slack vs Microsoft Teams

Sebastiaan Smits By Sebastiaan Smits · Published October 8, 2026 · Updated October 8, 2026

Slack is a chat product first: channels, threads, huddles and a large app directory, sold per user. Microsoft Teams is a hub inside Microsoft 365, where chat, meetings and channel files share one window and one identity system. Companies that wire many outside apps into their chat lean toward Slack; companies already paying for Microsoft 365 usually find Teams already on the bill.

Side by side

SlackMicrosoft Teams
What it isThe original business chat platform, now part of SalesforceMicrosoft's chat, channel and meeting hub
Best forCompanies living in many appsMicrosoft 365 organizations
HeadquartersUnited StatesUnited States
Pricing modelPer user / monthBundled with Microsoft 365
PricingFree plan with 90-day history; Pro €6.75, Business+ €15 per user per month annual; Enterprise+ quoted around €45 per user.Included in Microsoft 365 business plans, with a free version for basic use; confirm current prices on Microsoft's site.
Free optionFree planFree plan
Place in our team chat software ranking#4 of 13#5 of 13
Websiteslack.commicrosoft.com

Both are reviewed in full in Best Team Chat Software in 2026. Position in that ranking can be paid for; the wording of a review or of this comparison cannot. Placement disclosure.

Which one to choose

Choose Slack if

your team works across many outside tools (ticketing, CRM, code host), wants shared channels with customers or partners, and values a fast, chat-centered interface over an all-in-one hub.

Slack, #4 in the ranking · Visit Slack →

Choose Microsoft Teams if

you already license Microsoft 365, want chat, meetings and channel files in one place, and need retention, guest access and policies run from the same admin center as email.

Microsoft Teams, #5 in the ranking · Visit Microsoft Teams →

Where they differ

Wiring chat into other tools

Slack's pricing page lists unlimited app integrations on every paid plan, against 10 on the free plan, and the Slack Connect feature lets two companies share a channel instead of trading email. Teams reaches outside apps too, but our category notes describe its strength as the Microsoft suite, not the open directory. Where the chat is the front door to a dozen other systems, Slack is the better fit.

Edge: Slack

Files and meetings in the same place

Microsoft documents that each team has a SharePoint site and each channel a folder in its document library, so tenant-wide compliance rules apply to files shared in conversations. Meetings run in the same client, up to 300 people on Business Basic, Business Standard, Business Premium and Teams Essentials. Slack offers huddles and file sharing, but group huddles need a paid plan. For a Microsoft shop, Teams keeps documents and calls closer to the conversation.

Edge: Microsoft Teams

Size and structure limits

Microsoft's limits page allows up to 25,000 members in a team, 1,000 channels per team and shared channels with up to 50 other teams, though shared channels support only Microsoft Entra work or school accounts and do not support bots or connectors. We found no comparable published ceilings on Slack's pricing page, so we cannot compare the two on scale. Teams is documented in more detail, but detail is not the same as a better product.

Edge: even

What the entry price buys

Slack's page, shown to a European visitor, lists Pro at EUR 6.75 per user per month billed annually (EUR 8.25 monthly) and Business+ at EUR 15 (EUR 18 monthly), with Enterprise+ at EUR 45 on annual billing only. The free plan keeps 90 days of history. We could not load a current Teams price list this session, and our category file says only that Teams is included in Microsoft 365 business plans with a free version for basic use. A Microsoft 365 customer pays nothing extra for chat, which matters to them, but we cannot put a Teams price next to Slack's.

Edge: even

Admin burden and clutter

Our category notes describe Teams as crowded, with uneven search, heavy channel structure and guest access that takes administrator work. Slack's weakness is cost growth with headcount and compliance features reserved for Enterprise+. A small team without an IT administrator will tolerate Slack's cost more easily than Teams' setup, though a large tenant already staffed for Microsoft 365 will see it the other way around.

Edge: Slack

Tally: Slack 2, Microsoft Teams 1, even 2.

When neither fits

Neither is right for a team that must self-host or keep data under its own control. Slack is a single hosted product owned by Salesforce, and Teams depends on a Microsoft tenant. Mattermost and Element are the self-hosted options in our ranking.

See Pumble and Mattermost among the 13 products in Best Team Chat Software in 2026.

Questions and answers

Does Slack have a free plan?

Yes. Slack's pricing page lists a free plan with 90 days of message history, up to 10 app integrations, 1:1 huddles and 1:1 external messages. Pro and above unlock unlimited history and integrations and group huddles.

Is Microsoft Teams free if we already have Microsoft 365?

Teams is included in Microsoft 365 business plans according to our category file, and Microsoft documents meetings of up to 300 people on Business Basic, Business Standard, Business Premium and Teams Essentials. We could not load Microsoft's current price list this session, so check what your licence covers before assuming nothing extra is needed.

Can Slack and Teams chat with people outside the company?

Both can. Slack Connect shares a channel between organizations; the free plan allows only 1:1 external messages and paid plans allow group channels. Teams shared channels let outside Microsoft Entra work or school accounts join, but do not support bots, connectors or message extensions.

How much does Slack cost per user?

On the page we fetched, shown in euros, Pro is EUR 6.75 per user per month billed annually or EUR 8.25 monthly, and Business+ is EUR 15 annually or EUR 18 monthly. Enterprise+ is EUR 45 per user, annual billing only. Prices can differ by region and currency.

Sources

Prices, plan limits and product facts on this page were checked against the vendors' own pages on October 8, 2026. Vendors change both without notice, so treat the figures as of that date.